1. Field of the Invention
This invention relates to at least one wave guide for de Broglie waves and material comprising wave guides for de Broglie waves, and its applications and manufacture, and more particularly to an apparatus comprising at least one wave guide for de Broglie waves and at least one particle interacting with one or more wave guides for de Broglie waves.
2. Description of the Related Art
The invention concerns production means for the manufacturing of a wave guide, a bundle of wave guides, material consisting of wave guides, a screen consisting of wave guides together with the materials, the screens and the products which are made from these screens, or the above mentioned material. One of these products is a mirror with a very high reflectance. Mirrors with a somewhat lower reflectance are known form the literature.
A. F. Harvey states on page 236 of "Coherent Light", published by Wiley-Interscience in London in 1970, that mirrors with a high reflectance can be made by vapour deposition on a insulator of 1/4-.lambda. layer of two dielectric media with different refractive indexes. Such multilayer mirrors do have the following 5 disadvantages:
1) Their bandwidth is limited. Harvey comments: Let n.sub.i be the refractive index of a layer of medium i and .DELTA..lambda. the width of the band, at a distance of the media 1 and 2 of (1/4) .lambda., .DELTA..lambda./.lambda.=(4/.pi.) arc sin {(n.sub.1 -n.sub.2)/(n.sub.1 +n.sub.2)} yields. The bandwidth can be enlarged by varying the thickness of the layers. Harvey gives as an example the fact that a multilayer mirror consisting of 35 layers, in the wavelength domain 300 nm.ltoreq..lambda..ltoreq.830 nm, can have a reflectance greater than 0.9.
2) The power that these mirrors absorb is too much for some applications e.g. in high power lasers.
3) They do not reflect exclusively according to Snellius' law and thus scattering of light occurs. Harvey gives as an example a 15 layer mirror designed for a wavelength of 1.06 .mu.m, which transmits 0.05%, reflects 99.34% and absorbs or scatters about 0.6%. Jeffrey W. Griffin et al show in Applied Optics (see vol. 25, no.10, page 1532, 1986), that the scattering arises from two sources which cause surface scattering and volume scattering respectively. They state that volume scattering increases with the number of layers and they mention a 15 layer mirror, designed for a wavelength of 0.633 .mu.m having a reflectance of 99% and a volume scattering of 1%. Therefore in practice the reflectance as a function of the number of layers has a maximum which is smaller than 1.
4) They do not have a sharply determined cutoff wavelength. Therefore it is impossible to use these mirrors e.g. to cut off the spectrum of Nd-YAG laser in such a way that a smaller domain of the spectrum would be available in order to sharpen the focus of the Nd-YAG laser light.
5) Their applicability with respect to short wavelengths is limited due to the fact that at a certain wavelength the reflective ability of the normal reflection decreases as a function of the frequency.
The said invention, in most cases, does not have these disadvantages, or if so, to a lesser degree.